1. Field of the Invention
The present invention generally relates to an image forming system and, more particularly, to an image forming system including an image forming apparatus for printing image data and an image data outputting apparatus, such as a word processor or a computer, for sending the image data to the image forming apparatus.
2. Description of the Related Art
Recently, energy efficiency and energy saving equipment has become a requirement for almost all office products, and many different types of office equipment having an energy saving function have been developed. For example, a facsimile apparatus having an energy saving function is now on the market. This apparatus reduces power consumption by deactivating a high-power consuming unit, such as a heater used in a printing unit, during a reception waiting mode.
In the conventional facsimile apparatus having such an energy saving function, when the facsimile apparatus is set in the energy saving mode, the energy saving mode is canceled by a manual operation of an operator inputting an instruction through an operational panel of the facsimile apparatus so as to turn on power of each part of the facsimile apparatus.
In the above-mentioned conventional facsimile apparatus, since the cancellation of the energy saving mode must be made by a manual operation, it is inconvenient for the operator to use such an energy saving mode.
In order to eliminate such inconvenience, Japanese Laid-Open Patent Application No. 5-95463 discloses a facsimile apparatus which cancels the energy saving mode by automatically turning on power when a calling signal transmitted through a telephone line is detected.
In the facsimile apparatus disclosed in the above-mentioned patent document, since the cancellation of the energy saving mode is performed by detecting the calling signal, the cancellation can be achieved only when the facsimile apparatus is called by a remote facsimile apparatus.
Recently, many functions are provided to facsimile apparatuses, and printing units provided in facsimile apparatus es are provided with a communication function. The communication function provided to the printing unit allows the facsimile apparatus to be used as a printer by an external device. That is, the facsimile apparatus is connected to an external device such as a word processor or a personal computer so that the facsimile apparatus is used as a printer for the external device.
In such circumstances, the above-mentioned conventional facsimile apparatus cannot provide appropriate energy saving performance since the cancellation of the energy saving mode is performed by a manual operation or detection of a calling signal. More specifically, when the facsimile machine is connected to a word processor or a personal computer as to be used as a printer, the cancellation of the energy saving mode in the conventional facsimile apparatus cannot be performed automatically since the word processor or the personal computer does not generate and output a calling signal. Thus, there is a problem in that the conventional facsimile machines having the energy saving mode are inconvenient to use as a printer for an external device.
Additionally, in a facsimile apparatus or a printer, since only a high power consuming unit such as a printing unit is deactivated in the energy saving mode, further reduction in power consumption is desired.